About Using the x2APIC Option

You can enable or disable the x2APIC architecture from the BIOS Setup Utility.
Access the BIOS Setup Utility, select Advanced > CPU Configuration > x2APIC >
Enabled or Disabled. Then Exit and save changes. See the following screen example.

Note the following conditions regarding the x2APIC option:

Oracle Enterprise Linux 5.6: Disable x2APIC for installation. After installation set back to enable x2APIC if
UEK is going to be used.